Needle threader and presser foot



P 10, 1940. J. c. LOUNSBURY NEEDLE THREADER AND PRESSER FOOT Filed Sept. 28, 1959 mll John 0: Zounsbuqy ATTORNEYS WITNESS Patented Sept. 10, 1940 UNITED STATES PATENT OFFICE 3 Claims.

This invention relates to a needle threader for sewing machines of the general type described in my co-pending application filed July 17, 1939, Serial No. 284,988, and has for an object to provide a needle threading device which is attached to and becomes part of a sewing machine.

A further object is to provide a presser foot having a needle threading device as a part of, and included in, the presser foot.

A further object is to provide a presser foot and threader which will eliminate dulling and breaking of needle points due to being pulled out of alinement while sewing.

A further object is to provide a presser foot and threader which will automatically aline the threading pin with the eye of the needle, which eye is normally set at an angle of approximately ten degrees out of parallel with the front of the sewing machine, and which will thrust the threading pin in a straight line through the needle eye.

A further object is to provide a needle threading device and presser foot which also can be used for sewing.

A further object is to provide a needle threading device which will thread the needle automatically after the thread is manually inserted in the device.

A further object is to provide a needle threading device which will be simple in construction, and which will embody only two moving parts, operated by a single spring.

With the above and other objects in view the invention consists of certain novel details of construction and combinations of parts hereinafter fully described and claimed, it being understood that various modifications may be resorted to within the scope of the appended claims without departing from the spirit or sacrificing any of the advantages of the invention.

In the accompanying drawing forming a part of this specification:

Figure l is a perspective view of an automatic needle threader and presser foot constructed in accordance with the invention.

Figure 2 is a plan view of the device.

Figure 3 is a longitudinal sectional view of the device showing the threading pin in normal position.

Figure 4 is a longitudinal sectional view of the device showing the threading pin riding in the longitudinal groove of the needle.

Figure 5 is a longitudinal sectional view of the device showing the threading pin thrust through the eye of the needle to thread the needle.

Figure 6 is a longitudinal sectional view of the device showing the trigger locking pin.

Figure 7 is a detail cross sectional view taken on the line 1-1 of Figure 3.

Figure 8 is a detail crosssectional view taken on the line 8-8 of Figure 4. v 5

Figure 9 is a detail cross sectional view showing the needle threaded and the loop in the thread clamped in the device.

Figure 10 is a plan view of the L arm and threading pin.

Figure 11 is a plan view of the trigger.

Figure 12 is a detail sectional view, drawn to enlarged scale, showing the thread receiving groove in the end of the threading pin. 16

Referring now to the drawing in which like characters of reference designate similar parts in the various views, I0 designates a substantially rectangular casing open at the bottom and at the rear end. A plate II is disposed on the bottom of the casing and forms a presser foot, the long and short legs l2 and I3 of the presser foot projecting beyond the front wall 20 of the casing. The plate is provided at the rear end with a bracket comprising an upwardly extending rear leg I4 and a forwardly horizontally extending leg [5 which is provided with a notch Hi to receive the conventional squared neck of a sewing machine presser foot stem I1. The conventional nut I8 is screwed down onto the leg l5 to secure the presser foot in position to receive the needle l9. Although the presser foot is shown as detachable it may be formed integral if desired. A screw 2| secures the casing to the presser foot.

The working parts of the device are housed 35 within the enclosure formed by the casing ID, the presser foot II, upwardly extending leg M of the presser foot bracket and relatively thick front wall 20 of the casing.

The front wall of the casing is provided with a needle receiving opening 22 which opens 40 through the top of the casing and through the presser foot. The opening is provided with a lateral recess 23 to receive the thread 24. A narrow passageway 25 establishes communication between the opening and a recess between the presser foot legs [2 and I3 having rounded guide walls 26. A loop of the thread is passed into the opening 22 and lodges in the lateral recess 23, as shown in Figure 1. 50

The threading pin 21, shown in detail in Fig-' ure 12, is provided with a concave surface 28 at its tip to receive the thread. The threading pin is pivotally mounted on a pivot pin 29 carried by the long leg 30 of an L lever, the short leg 3| 55 of which is pivoted intermediate its ends on a pivot pin 32 which extends upwardly from the presser foot. Due to the L lever being pivoted at an offset point from its elbow the pivoted end of the threading pin 21 will move forwardly toward the front wall 20 of the casing as well as laterally along the inner surface of said front wall so that the pin will have accurate rectilinear movement through the threading eye 33 of the needle, which eye is ordinarily set at an angle of approximately 10 degrees out of parallel with the front of the sewing machine.

The threading pin 21 rides: along the longitudinal groove 34 of the needle, and during upward movement of the needle, brings the thread into registration with the threading eye 33 whereupon the L lever, under urge of a controlling spring 35, later described, drives the threading pin through the eye and back of a leaf spring jaw 36 which extends along the rear face of the front wall 20 of the casing on the opposite side of the thread receiving opening 22 from the threading pin2l.

A trigger 31, best shown in Figure 11, is pivotally mounted on a pivot pin 38 which rises from the presser foot ll laterally of the long leg of the L lever. A slot 39 is disposed in the trigger to receive the pivot pin so that the trigger may have rectilinear'as well as pivotal movement. The trigger is provided with a right angularly disposed extension 40 which is adapted to engage the free end of the L lever at the threading pin to move the lever to withdraw the threading pin after the threading pin lodges the loop of the thread back of the leaf spring jaw 36 as will presently appear. The trigger is provided with a finger 4| adapted to extend back of the threading opening 22 and lodge against a stop pin 42 in neutral position to permit the device being used while sewing.

The trigger 31 is also provided with an upstanding pin 43 which projects through an arcuate slot 44 formed in the top wall of the casing III, which slot terminates in a bayonet slot 45, as best shown in Figure 2. The purpose of the pin 43 is to cook or set the trigger by manually pulling the pin through the arcuate slot 44 until it lodges in the bayonet slot 45.

The spring 35 above referred to is a spiral spring. One end 4! of the spring is engaged against the free end of the short leg 3| of the L lever. The other end 43 of the spring is engaged against the trigger cocking pin 43. When the cocking pin is moved to operative position the spring will be tensioned and presses against the short leg of the L lever to move the long leg of the lever to the position shown in Figure 4, in which position the threading pin 21 carries the loop of the thread into the longitudinal groove 34 of the needle l9, the needle having been previously lowered through the opening 22, as shown in Figure 7. At the same time the extension 40 engages the stop 42 so that as the cooking pin lodges in the bayonet slot 45 the trigger will be shifted on the pivot pin 38 to lodge the pivot pin 38 at the inner end of the slot 39 in the trigger as also shown in Figure 4.

A thin arcuate plate 49 projects from the trigger 31 adjacent the cooking pin 43. This plate normally covers the arcuate slot 44 and bayonet slot 45 to prevent access of foreign matter to the two working parts, namely, the L lever 30 and the trigger 31.

In operation the fly wheel of the sewing machine is turned to lower the needle l9 through the opening 22 as shown in Figure 7. The op erator then pulls the trigger cocking pin 43 from the position shown in Figures 1 and 2 rearwardly along the arcuate slot 44 until it lodges in the bayonet slot 45. In this position the cooking pin iocks the trigger in the cocked position shown in Figure 4. During this movement of the trigger the spring jaw 36 is in open position and the spring 35 has been placed under compression to exert pressure on the L lever, causing the lever to move the threading pin 21 and loop of the thread into the longitudinal groove 34 of the needle.

Also during this movement the arm 40 of the trigger will have-been manually rocked to lodge against the stop pin 42 and to shift the trigger on the pivot pin until the pivot pin lodges in the opposite end of the slot as shown in Figure 4. The device is now ready to operate.

The fly wheel is then turned back to raise the needle through the opening 22 as shown in Figure 8. At the movement the eye 33 of the needle registers with the threading pin 21, the spring 35 urges the threading pin through the eye of the needle and the loop of the thread is carried between the open leaf spring jaw 36 and the inner face of the front wall 20 of the casing.

Simultaneously, the long leg 30 of the L lever strikes against the elbow of the trigger and pushes the trigger laterally to its limit of movement on the pivot pin 38 to unlock the cooking pin 43 from the bayonet slot 45, as shown in Figure 5. Thereupon the tension spring 35 rocks the trigger to neutral position shown in Figure 3 and during such movement a curved wall 49' on the trigger is brought into engagement with the leaf spring jaw 36 and closes the jaw to clamp the loop of the thread substantially stationary against the wall 20 of the casing, while the threaded needle is withdrawn from the threading opening as shown in Figure 9.

At the instant the trigger is moved as just described, the extension 40 pushes against the free end of .the long leg 30 of the L lever to withdraw the threading pin 21 to its neutral position so that the threaded needle may continue its upward stroke to clear the threading device, as shown in Figure 9.

As a safety feature it is desirable that the trigger cannot be cooked if there is no needle in the opening 22 otherwise the sewing machine needle would be broken by contact, with the threading pin. Should there be no needle in the opening, and the cooking pin 43 be moved up to the bayonet slot 45, the spring 35 will rock the lever 3| and the long leg 30 thereof will act as afollower on the extension 40 of the trigger causing the trigger to have pivotal movement only on the pivot pin 38. As a. result the cocking pin 43 cannot be thrust into the bayonet slot 45 for the trigger must shift the length of the slot 39 on the pivot pin, that is, from the position shown inFigure 3 to the position shown there being an opening in the casing and in the presser foot in the path of a sewing machine needle and in the path of the threading pin adapted to receive a loop of thread, a leaf spring jaw in the casing on the opposite side of the opening from the threading pin, a lever in the casing connected to the threading pin for actuating the threading pin to push said loop of thread through the eye of the needle, a trigger mounted for pivotal and rectilinear movement in the casing and normally holding said jaw closed, means for cocking the trigger to permit the jaw to open, and a single spring in the casing engaging said trigger and said lever and adapted to be placed under compression when the trigger is cocked and urge the threading pin and loop of thread against the needle, said spring being adapted to expand when the threading pin passes through the eye of the needle and move the trigger to close the jaw on said loop of thread as soon as said threading pin passes through the eye of the needle and to subsequently engage said lever and move the lever to withdraw the threading pin from the eye of the needle.

2. The combination with a sewing machine presser foot, of a casing assembled as a unit with the presser foot, an L-shaped lever in the casing having a long leg and a short leg, a pivot pin for the lever disposed intermediate the ends of said short leg, a threading pin pivoted on the end of said long leg terminally engaging the front wall of said casing, pivotal movement of the lever moving the pin pivotally and in a rectilinear direction to accurately pass through the eye of a sewing machine needle, there being an opening in the casing and in the presser foot in the path of said needle and in the path of said threading pin adapted to receive a loop of thread, a jaw in the casing on the opposite side of the opening from the threading pin, movement of said lever actuating the threading pin to push said loop of thread through the eye of the needle and into position to be clamped by said jaw, a trigger mounted for pivotal and rectilinear movement in the casing and normally holding said jaw closed, means for cooking the trigger to permit the jaw to open, and a single spring in the casing engaging said trigger and the short leg of said lever and adapted to be placed under compression when the trigger is cooked and urge the threading pin and loop of thread against the needle, said spring being adapted to expand when the threading pin passes through the eye of the needle and move the trigger to close the jaw on said loop of thread as soon as said threading pin passes through the eye of the needle and to subsequently engage said lever and move the lever to withdraw the threading pin from the eye of the needle.

3. The combination with a sewing machine presser foot, of a casing assembled as a unit with the presser foot, a lever pivoted in the casing, a threading pin carried by the lever, there being an opening in the casing and in the presser foot in the path of a sewing machine needle and in the path of said threading pin adapted to receive a loop of thread, a jaw in the casing on the opposite side of the opening from the threading pin, movement of said lever actuating the threading pin to push said loop of thread through the eye of the needle and into position to be clamped by said jaw, a trigger in the casing having an extension adapted to engage said lever, a pivot pin for the trigger, there being a slot in the trigger receiving the pivot pin, a cocking pin extending from the trigger adapted to rock and shift the trigger lengthwise of the slot on the pivot pin, there being an arcuate slot in the casing receiving said cocking pin and having a bayonet slot adapted to yieldably receive the cocking pin and hold the trigger cocked, said trigger in cocked position permitting said jaw to open, and a single spring in the casing engaging said trigger and said lever and adapted to be placedunder compression when the trigger is eockedand urge the threading JOHN C. LOU'NSBURY. 

